Electro-photographic processes comprising a plurality of process means require more maintenance as compared with thermosensitive processes or ink-jet processes. By integrally assembling a process cartridge with a plurality of the process devices such as a photosensitive drum, a charger, a toner case, and a cleaner, the maintenance may be reduced. But, usage of conventional process cartridges make the cost of copying expensive since the process cartridge must be replaced when toner is used up. The present invention provides a reusable process cartridge which facilitates lowering the cost of copying.